Summary: In the US, in recent years, there has been a number of reported fatal episodes of transfusion transmitted bacterial infections leading to septicemia and parasitic infections causing malaria, babesiosis, and chagas disease. Recent data suggest that NAT can be used to detect infectious agents in blood and blood products. These tests potentially offer sensitive, reliable, and practical methods to screen blood for infectious agents. NAT have several advantages over conventional detection methods of direct in vitro culture, antibody tests and microscope-based identification. Using available PCR-based detection assays, 5'-nuclease Taqman PCR assay and microarray DNA tests, it is feasible to develop NAT for high through put pathogen screening of individual or pooled blood samples. To date no licensed nucleic acid based test is available to screen donor blood for infectious agents other than for HIV and hepatitis viruses. We have developed a PCR-based assay that detects a single ring stage Plasmodium falciparum malaria parasite in 1 ml of blood, with sensitivity 20-fold higher than that of conventional stained thick blood films. This NAT technology will be further developed to allow detection of infectious agents that could be potentially present in donor blood.